带分流叶片混流式水泵非定常流动特性研究

Unsteady Flow Characteristics of Mixed-flow Pumps with Splitter Blades

为研究在流固耦合作用下分流叶片对混流式水泵的性能影响,以某型号的大流量混流式水泵作为研究对象,采用双向流固耦合方法和动网格变形技术对有/无分流叶片混流泵进行流场和结构场计算。对比分析了有/无分流叶片对混流泵非定常流动特性和动力学特性的影响。研究发现,分流叶片的添加使得动静干涉产生的压力脉动幅值的最大值大幅降低,但减小了脉动衰减的速度。有/无分流叶片对轴向力平均值影响不大,但考虑流固耦合效应时轴向力有所减小并有波动产生。分流叶片的添加可以降低应力以及形变的波动幅值。叶片最大应力区主要集中于靠近叶轮轮毂及轮缘处,分流叶片的添加使得叶片最大应力减小,且改善了应力变化梯度,使得应力分布更加均匀。分流叶片的添加也使得叶片形变在圆周方向更加均匀,改善了形变分布的偏心问题。研究结果可以为混流泵叶片的优化设计提供相应参考。

In order to study the influence of splitter blades on the performance of mixed-flow pumps with the effects of fluid-solid interaction,a certain type of mixed-flow pump with large flow was used as the research object,and the two-way fluid-solid interaction coupling method with dynamic mesh deformation was used.The influence of the presence of splitter blades on the unsteady pressure fluctuations and the resulting structural dynamic characteristics of the mixed-flow pump were studied.It was found that the presence of splitter blades greatly reduced the maximum value of pressure fluctuation amplitude which was induced by rotor stator interaction.However,the presence of splitter blades had an effect of reducing the rate of fluctuation dissipation.The splitter blades had little influence on the average value of the axial force.When the effects of fluid-solid interaction were considered,the average value of axial force was reduced and there were fluctuations.Besides,the presence of splitter blades had an effect of reducing the fluctuation amplitude of total stress and deformation.The maximum stress area occurred in the intersection of the blade and the hub/shroud.The maximum stress of the blade was reduced by the presence of splitter blades,and the stress gradient was reduced,resulting a more uniform stress distribution.The blade deformation was more uniform in the circumferential direction due to the presence of splitter blades,and the eccentricity of the deformation distribution was reduced.The research results could provide some references for the optimal design of the mixed-flow pump.